Artificial arm



E. R. BIRCHARD.

ARTIFICIALARM.

APPLICATION FILED JUNE 25. 1919.

Patented J ah. 13, 1920.

INVENTUR.

UNITED STATS PATENT orrron.

ESLIE R. BIRCI-IARD, OF TORONTO, ONTARIO, CANADA, ASSIGNOR TO THEDEPARTMENT OF SOLDIERS CIVIL RIB-ESTABLISHMENT, INVALIDED SOLDIERSCOMMISSION OF THE DOMINION OF CANADA.

Application filed June 25,

- To all whom it may concern:

Be it known that I, Esmr. R. BIRCHARD, a subject of the King of GreatBritain, residing in the city of Toronto, in the county of York,Province of Ontario, Canada, have invented certain new and usefulImprovements in Artificial Arms, of which the following is aspecification.

This invention relates to arms particularly intended for use inamputation cases where the forearm has been amputated a short distancebelow the elbow. In such cases when the elbow is closed, the shortforearm practically disappears into the upper arm, thus making itimpossible to provide an ordinary arm jointed in the usual way andoperated by the stump. I overcome this difficulty by providing a jointby means of which the artlficial forearm moves through a longer are thanthe stump of the natural arm, so that the artificial forearm may beswung up to its limit of movement while the natural stump is stillapproxi mately at right angles to the upper arm.

The invention is illustrated in the accompanying drawings in whichFigure l is a side elevation of my improved arm;

Fig. 2 a plan view of the same; and

Fig. 3 a side elevation of the joint with the parts in the positionsthey assume with the forearm swung up.

In the drawings like numerals of reference indicate corresponding partsin the different figures.

l is the artificial forearm, which may be of any construction, and 2 thesheath or jacket adapted to be secured to the wearers upper arm. 3 isthe bucket for the stump of the forearm. Side irons 4 are secured to theartificial forearm, side irons 5 to the sheath 2, and side irons 6 tothe bucket 3. These irons are all pivoted together at 7.

Pivot-ally connected to each side iron 6 is a link 8 which is connectedwith a stud 9 slidable in a slot 10 in the side iron 5. A link 11 isconnected to the stud 9 and is pivotally connected with the side iron 4closer to the pivot 7 than the pivot of the Specification of LettersPatent.

ARTIFICIAL ARM.

Patented Jan. 13, 1920.

1919. Serial No. 306,708.

' link 8. The result of this construction is that the artificial forearmis swung through a larger arc than that through which the bucket for thestump is moved, and the object of my invention is thus attained. Theoperating connections between the bucket and the forearm member arepreferably duplicated at each side of the arm but of course one set onlymight be employed.

The side irons 6 of the bucket 3 are each preferably provided. with alug 12, which by contact with the side irons of the forearm limit theextension of the forearm.

In practice many changes may be made in the details of constructionwithout departing from the spirit of my invention.

What I claim as my invention is:

1. An artificial arm comprising a forearm member, an upper arm sheathand a bucket in which the operating connections between the bucket andthe forearm member comprise a part mounted to slide longitudinally ofthe upper arm sheath; a link pivotally connected with the sliding partand with the buck t member; and a link pivotally connected with thesliding part and the forearm member, the distance between thepivot-point of the bucket link to the bucket and the pivot-point of thebucket to the upper arm sheath being greater than the distance betweenthe pivotpoint of the forearm link to the forearm member and thepivot-point of the forearm to the sheath.

2. Anartificial arm comprisinga forearm member, an upper arm sheath anda bucket in which the forearm member, the upper arm sheath and thebucket are each provided with side irons at each side pivoted on acommon pivot and provided with operating connections between the bucketand the forearm member comprising a part sliding in a slot formedlongitudinally of one of the side irons of the sheath; a link pivotallyconnected at one end to the sliding part and at its other end to one ofthe side irons of the bucket; and a link pivotally connected at one endto the sliding part and at its other end to one of the side irons of theforearm member at a point closer to the common pivot of the side ironsthan the pivot point of the link of the bucket member from the said.common pivot.

3. In an artificial arm, the combination of a forearm member; an upperarm sheath;

a bucket for a forearm stump, the bucket and forearm member beingpivotally connected with the sheath; and link connections 1,s27,93s v E.R. BIRCHARD.

